MLB issued a statement saying, "Urías has been reinstated from Administrative Leave while the investigation into a matter governed by the Joint Domestic Violence, Sexual Assault and Child Abuse Policy continues."

MLB says they are still investigating the matter.

TMZ Sports broke the story ... Urias -- one of the hottest young pitchers in baseball -- was arrested May 13 after he allegedly got physical with his girlfriend in the parking lot of the Beverly Center.

Officials reviewed video of the incident and determined there was enough evidence to make an arrest. He was hauled to a nearby station and spent the night behind bars.

As we previously reported, prosecutors feel the case against Urias is "weak" based on the evidence -- which doesn't appear to show Urias had an "intent to injure" when he put his hands the women.

Instead, we're told it seems like Urias was trying to prevent his GF from leaving the parking lot -- and she went to the ground as a result ... but it did not appear as though he wanted to hurt her.

MLB officials launched their own investigation but according to the L.A. Times, they weren't able to get their hands on the video.

Urias had been placed on a 7-day administrative leave by MLB -- but now that's over and Urias can return to the mound.

The criminal case against Urias is still technically active ... but we're told that should wrap up shortly.